SLAC Today is
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In this issue:
Fermi Telescope Celebrates One Year of Science
Fermi Telescope Caps First Year With Glimpse of Space-Time
Reminder: All-Hands Safety and Security Briefings Today
SLAC Green Note: Check Out the Label
Thursday - October 29, 2009 |
Fermi Telescope Celebrates One Year of ScienceJust over a year after the Fermi Gamma-ray Space Telescope began taking science data, the collaboration is celebrating its many noteworthy results. "With Fermi, we're seeing the gamma-ray sky at timescales we've never been able to probe before; we also see an energy range previously inaccessible to us," Fermi Project Scientist Julie McEnery said yesterday during a NASA media event publicizing the first year of Fermi telescope results. "With these missing pieces, we're finding many new things in the sky." Read more... Fermi Telescope Caps First Year With Glimpse of Space-TimeDuring its first year of operations, the Fermi Gamma Ray Space Telescope captured more than 1,000 discrete sources of gamma rays—the highest-energy form of light. Capping these achievements was a measurement that provided rare experimental evidence about the very structure of space and time, unified as space-time in Einstein's theories. "Physicists would like to replace Einstein's vision of gravity—as expressed in his relativity theories—with something that handles all fundamental forces," said Peter Michelson, principal investigator of Fermi's Large Area Telescope. "There are many ideas, but few ways to test them." On May 10, 2009, the Fermi telescope and other satellites detected a so-called short gamma-ray burst, designated GRB 090510. Astronomers think this type of explosion happens when neutron stars collide. Ground-based studies show the event took place in a galaxy 7.3 billion lightyears away. Of the many gamma-ray photons the LAT detected from the 2.1-second burst, two possessed energies differing by one million times. Yet after traveling some seven billion years, the pair arrived just nine-tenths of a second apart. "This measurement eliminates any approach to a new theory of gravity that predicts a strong energy-dependent change in the speed of light," Michelson said. "To one part in 100 million billion, these two photons traveled at the same speed. Einstein still rules." For more on the new result, see: Gamma-ray Burst Restricts Ways to Beat Einstein's Relativity, Symmetry Breaking, and the full NASA news release... (Note: NASA page may display incorrectly in Internet Explorer; it displays correctly in Firefox.) Reminder: All-Hands Safety and Security Briefings TodayEveryone in the SLAC community is asked to attend one of four 70-minute sessions for the Annual Safety and Security Briefing in Panofsky Auditorium today. There will be free SLAC flashlights, calendars, pens and other giveaways for those who attend. The program will include: 1. Event host, introduction and event overview - Brian Sherin Four 70-minute sessions will take place in SLAC's Panofsky Auditorium. Please use the schedule below to determine which session you should attend to help avoid overfilling any one session. 8:30–9:45 a.m., last names starting A–F If you have questions, please contact Terry McMahon at (x3465) or Brian Sherin (x5082). After the fair, please fill out the online evaluation. SLAC the ES&H Division will be awarding five $10.00 Starbucks gift certificates in a random drawing to five lucky winners who complete the form. Winners will be announced on November 5. SLAC Green Note:
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